An internal combustion engine is used to transfer the fuel (e.g. air and gasoline) to mechanical energy to operate an engine. A complete process of transferring the fuel to mechanical energy is called engine cycle. The operation of the engine commonly includes a plurality of engine cycles.
An engine cycle generally includes four strokes: intake, compression, power transformation and exhaust. Intake is for generating vacuum by the pressure difference to the atmosphere. Air is filtered, and the filtered air is pulled in by the vacuum; then the filtered air is mixed with a gasoline jetted by a nozzle in a cylinder block. Compression is for compressing; the mixed gasoline in the cylinder block. Power transformation is for burning the mixed gasoline to expand the volume thereof, thereby pushing the piston to generate mechanical energy. Exhaust is for exhaling the waste gasoline from the cylinder block. For increasing the performance of the cylinder block, the burning efficiency of the gasoline should be increased. Therefore, it is very important to control or increase the air flow.
In a conventional injection type internal combustion engine, the open level of the intake throttle valve is increased with the pressing amount of the accelerator pedal. Greater depression of the accelerator pedal, promotes higher open level of the intake throttle valve, and therefore larger amounts of air pulled in. When the amount of air pulled in is greater, an air flow sensor is used to detect the air flow, and the detecting results will be transferred to a gasoline-injecting controlling system, then more amount of gasoline will be injected to increase air-fuel ratio, thereby the efficiency of the internal combustion engine will be increased. However, the conventional air flow sensor has time error from detecting to sensing so that the detecting data is not accurate. Thus, the amount of real air flow will be smaller than the amount that is required to be mixed with the gasoline. Moreover, a time error will also be occurred when the air flows in, thereby lowering air-fuel ratio.
The aforementioned situations usually occur when the vehicle starts from rest state or starts from a lower vehicle speed to a higher vehicle speed. When the accelerator pedal is pressed to increase the vehicle speed, the vehicle may tremble or the vehicle will be stuck. Furthermore, in an environment having thin air, the amount of the air flow is not enough, therefore air-fuel ratio is low, and thus the power of the inner combustion engine is low, thereby lowering the climbing ability of the vehicle.
A turbo boosted type internal combustion engine which uses a turbocharger 56 may now be used in vehicles in the marketplace. The operation principle for turbo boost engines is that the boost type internal combustion engine is to use the exhaust air to drive a turbine blade, and the air compressor disposed in one end of the turbine axis is used to compress the air that enters the compressed air, and is provided to the inner combustion engine for burning. However, when compressing the incoming air for use in the combustion system, the air temperature is greatly increased causing less combustion efficiencies.
Intercooler 42 shown in FIG. 2 are accordingly implemented when a turbocharger is used in the engine assembly. The intercooler 42 is a heat exchanger that is used to cool air that has been compressed by either a super-charger or a turbocharger for the engine. The intercooler 42 is generally placed somewhere in the path of air that flows from the turbo/supercharger to the motor, and is typically a separate unit adjacent to the engine as shown in FIG. 2. An intercooler 42 is needed because it is undesirable to have excessively hot air used in an engine 38 given that hot air is less dense and therefore contains less molecules of oxygen per unit volume. Accordingly, there is less air for the motor in a given stroke and less power produced. Moreover, hot air also causes a higher cylinder temperature which can aid in pre-detonation of the combustion cycle which results in inefficient engine operations. Accordingly, it is desirable to provide an intercooler 42 for engines using turbochargers in order reduce the intake air temperature.
The mounting of a traditional intake manifold assembly 36 to an engine typically is comprised of several steel brackets, fasteners, or other joining structures such as hooks or clamps as shown in FIG. 1. The use of several intermediate components which attach on one side to the engine cover and on the other side to an engine component (e.g., an air intake manifold or a cam cover) creates many potential sites for NVH (noise, vibration, and harshness) problems such as squeak and rattle. Moreover, given that a traditional intake manifold assembly 36 generally requires fasteners 40 to be implemented at fastener sites 50 at both upper and lower sides of cylinder head 52 (as shown in FIG. 1), it may be particularly challenging for an assembly worker to access the lower fastening areas for the traditional intake manifold 36 due to small clearances between the engine parts. Moreover, the use of mechanical fasteners 40 usually means at least two fastening components are implemented on each of the upper and lower fastening sites for the intake manifold assembly onto the engine 38. The relatively large part count leads to added part costs and an associated increase in manufacturing time as well as assembly costs.
The air intake manifold which directs incoming air to the respective engine cylinders of a combustion engine has historically been fabricated from metal. More recently, various molded materials including thermoplastics, resins, and polymers have been used to manufacture intake manifolds. Preferred materials may include nylon or other polyamides which may further include filler materials such as glass fibers. A switch to plastic materials has achieved a reduction in weight, but reliance on brackets and fasteners with a high parts count have continued which enhances cost and assembly time.